1. Field of the Invention
The present invention relates to a film image input system and, in particular, to a film image input system which picks up the image of a long roll of developed film for a still camera by use of image pickup means, converts the image into a image signal, and outputs the image signal to a video monitor to thereby reproduce the film image on the video monitor.
2. Description of the Related Art
Conventionally, a film image input system which is adapted to reproduce the image of a roll of developed film for a still camera on a video monitor is known from USP.4,482,924, USP.4,485,406, USP.4,506,300, WO90/04301 and the like.
For example, as shown in FIG. 61, a conventional film image input system 36 includes a film feed system comprising a supply reel 38 for feeding a long roll of developed film 37 for a still camera and a take-up reel 40, an image pickup optical system 41 comprising an illumination unit 41A and a taking lens 41B, an image sensor 48A formed of a CCD, and an image signal process circuit 48B.
The above-mentioned film 37 is fed frame by frame between the illumination unit 41A and taking lens 41B. The image of the film 37 is illuminated by an illuminating light from the illumination unit 41A, and the illuminated image is picked up by the taking lens 41B and is then formed on the image sensor 48A. By means of this, the image on the film 37 is converted by the image sensor 48A into an image signal and is then signal processed by the image signal process circuit 48B. After then, the signal is output to the video monitor 49 as a video signal and is displayed on the video monitor 49. Also, some of this type of conventional film image input systems include a zoom mechanism, a film scan mechanism (X-Y moving mechanism), an image sensor rotating mechanism and other mechanisms.
However, according to the above-mentioned film image input system, due to the fact that, after the developed photo film 37 is directly rolled round the supply reel 38 and take-up reel 40 within the system, the film is fed, it is complicated to handle the photo film 37 and also there is a danger that the film 37 may be damaged or stained.
For example, as shown in FIG. 61, when using the supply reel 38 round which the photo film 37 is wound, the supply reel 38 is loaded in a film loading part 39, and with one end of the outer-most roll of the film being extended manually, the film 37 is inserted through the image pickup system 41 and is wound round the take-up reel 40, and the image surface of the film 37 is set to the focal surface of the image pickup optical system 41, which completes preparation for reproduction. Also, when taking out the film after the reproduction of the whole picture is completed, with one end of the outer-most roll of the film wound the take-up reel 40 being extended manually, the film is wound round the supply reel 38, and a switch for rewinding is depressed to thereby rewind the film. And, after completion of the rewinding of the whole film, a stop button is pressed down to take out the supply reel 38 from the loading part 39. The above-mentioned conventional film image input system requires the troublesome operations mentioned above.
Also, in Japanese Patent Application Laid-Open (Tokkai) No.1-289948, there is disclosed a film image input system using a film cartridge. However, this publication teaches no description of a film cartridge having a single spool and of an interface to the film image input system. For example, as shown in FIG. 62, when using a film cartridge 46 in which one end of a photo film 43 is fixed to a supply spool 44, the other end is fixed to a take-up spool 45, and these two spools 44 and 45 are spaced at a given distance from each other and are supported rotatably, the following problems arise:
That is, due to the fact that the design of a film image input system 42 is limited because the distance between the two spools 44 and 45 of the film cartridge 46 and also that the film cartridge 46 is constructed in such a manner to stretch over the image pickup optical system and thus the film image input system 42 must be larger in size in order to guarantee its loadability, a great space is necessary for storing the film image input system 42. Also, since the film surface is exposed by at least 1 frame on the front and rear sides thereof, there is a possibility that dust may enter from the exposed film surface. Further, the film cartridge 46 includes a picture frame 47 which makes it impossible to design freely a mechanism to coincide the focal surface of the image pickup optical system with the image surface of the film.
Also, in the case where the above-mentioned film has a magnetic recording layer, the arrangement of a recording/reproducing magnetic head with respect to the magnetic recording layer is limited by the shape of the film cartridge.
Further, the film is formed of acetate or polyester base material with a photosensitive emulsion coated thereon. For this reason, when compared with a magnetic tape such as an audio tape, a video tape and the like, the film is wider, easier to curl and has a greater rigidity, which gives rise to the following problems:
In other words, as shown in FIG. 63, the film (especially, the developed film) is heavily curled (see FIG. 63 (A)) and, if such curled film is to be stretched, it will be curved in the width direction thereof, as shown in FIG. 63 (B). Also, when one end of the film is wound automatically round the take-up reel, the leading end of the heavily curled film gets into the opposite side of the take-up reel to the winding side thereof, which makes it impossible for the film to be taken up. Further, since the great rigidity of the film provides a great restoring force for the film that has been taken up, the film is easy to flex or come loose in winding. Moreover, since the film has a broad width but has a limited number of frames, the film has a relatively small winding diameter, with the result that the film cartridge is different in shape from a tape cassette. For this reason, when loading the film cartridge into the cartridge loading part, there is required a cartridge loading mechanism which is different from a tape cassette loading mechanism.
Further, in order that the film image input system can always reproduce the film image in an excellent manner, it is necessary to take measures to prevent damage of the film and to correct the fading of the film image.
A film includes negative and positive films and, therefore, it is necessary to check whether a film is a negative film or a positive film. It is troublesome that, after whether the film is positive or negative is confirmed visually, the image signal processings in the film image input system are manually switched according to the kinds of the film. Also, it may happen that nothing is taken when the film image input system is started. In this case, it cannot be decided whether this is because the film is not set or because a frame in which nothing is taken is picked up.
When the winding and rewinding of the film is performed by use of a single reel motor, it is considered that a driving force is transmitted from the reel motor through a swing gear mechanism to a supply reel or to a take-up reel. However, the swing gear mechanism swings its head portion according to the directions of rotation of the reel motor and transmits the driving force to the supply or take-up reel only in the film winding direction thereof and, therefore, in the film loading (that is, when the film is sent out from the film cartridge), it is not possible to drive the supply reel in the film sending direction by use of the swing gear mechanism.
Also, when the film and image pickup means are moved relatively to each other to execute the X-direction and Y-direction scans of the film image, it is considered that the X-direction scan is carried out by sending the film. In this case, a speed ratio between the frame sending speed and the X-direction scan speed requires on the order of 20 times but this speed ratio cannot be realized only by changing the speed of rotation of the reel motor, with the result that the film frame sending and the X-direction scan cannot be executed by the single reel motor. Also, when executing the frame sending, a notch and the like indicating the position of the frame can be provided in every film frame and thus the film frames can be sent one by one accurately by detecting such notch and the like by use of a frame detector. However, as described above, if the X-direction scan is carried out by sending the film, then the same notch may be detected again in the next frame sending, as the scan position prior to the frame sending may be. That is, in this case, the same frame will be reproduced again.
In addition, in the case where the film has a magnetic recording layer and trimming information and the like are magnetically recorded into and reproduced from the magnetic recording layer in the frame sending, the frame sending speed must be maintained constant.